The long-term goal of our work is to propose a new type of well-defined aluminum hydroxide as a new candidate for a stronger and safer antacid. It will be used to reduce absorption of phosphorus for people with kidney failure, and in the treatment of heartburn, gastritis, and peptic ulcer. The mechanisms of interactions between these well-defined aluminum hydroxides and enzymes, proteins, antibiotics, living cells, and dietary supplements will be investigated in order to recommend this chemical as an antacid. The first hypothesis being evaluated is that this new aluminum hydroxide will release fewer aluminum species into the body; will have a higher acid-neutralizing capability, neutralization velocity, acid consuming capacity, and chemical activity; will have less sodium content compared to the antacids in current use. The second hypothesis is that aluminum compounds may act via direct cytoprotective action or by binding to pathogens. Dissolution testers will be used to evaluate in-vitro release of the drug from solid form as a function of time. Autotitrators will be used to calculate kinetic and conditional stability constants. The ability of infrared and Raman spectroscopies to determine structural and environmental information concerning biomolecules at low concentration in solution make them very powerful bioanalytical and biophysical techniques. In particular, the attenuated total reflection will be used for in-situ and in-vivo studies. For the first time, an atomic absorption spectrometer will be an indispensable tool in determining the amount of aluminum species released into the body for people taking aluminum-containing antacids. Textural and superficial characterization of the aluminum hydroxide powder will be done by adsorption isotherms.